Bottle cap



1 July 1954 A. B. MCGINNIS ET AL 2,534,168

BOTTLE CAP Filed Oct. 24, 1949 JNVENTOR. ARCHIBALD B. MGN IS. JOHN C. MGIN E. wl

ATTORNEYS Patented July 20, 1954 BOTTLE CAP Archibald B. McGinnis and John C. McGinnis,

Wheeling, W. Va., assignors to Wheeling Stamping Company, Wheeling, W. Va., a corporation of West Virginia Application October 24, 1949, Serial No. 123,194

Claims.

1 This invention relates to closures, such as threaded bottle caps, and more particularly, to an improved threaded bottle cap closure constructed from a flexible resilient material which flexible and resilient characteristics.

copolymers thereof, etc.

cap liner.

in the bottle.

its seal with the bottle neck.

cap closures.

stripping of the cooperating threads. By the provision of a square thread, the tightening force applied to a bottle cap is applied in an axial direction and is effective only to embed the lip of the bottle neck'in the structure of the cap to Although the provision of a As the bead moves into interwill deform. upon the application of force thereto. 5 provide a seal.

More specifically, this invention is concerned square thread resultsin a definite improvement, with a bottle cap closure constructed preferably it is not effective to completely eliminate the selffrom the plastic known as polyethylene. Alturning or loosening action of a bottle cap parthough the bottle cap closure, in the preferred ticularly where the threads of the cap are wetted practice of the invention, will be constructed from with a liquid such as liquid soap. polyethylene, it will be understood that the in- One of the principal objects of this invention vention is equally applicable to cap closures conis to provide a bottle cap closureinember molded structed from other materials exhibiting similar from a resilient flexible material of the character Other suitreferred to, and particularly the plastic material able materials, for example, are the various forms polyethylene, which will be effective to form a of plasticized vinyl resins, natural and synthetic liquid seal with the bottle when turned tightly rubber including thioko1,butadiene polymers and down on the neck thereof, and in which means Polyethylene is espe is provided for preventing the'cap from loosencially suitable because it is odorless, dense, and ing itself on the bottle neck even though the has a low coefficient of friction with glass so that threads are lubricated by a liquid material. To it is convenient to screw on and unscrew. this end, the cap and bottle neck are provided The construction of threaded bottle cap closwith cooperating and interlocking sealing parts ures from resilient flexible materials of the charcomprising an annular bead and a groove, the actor referred to, and particularly polyethylene, M annular bead being formed on either the internal has been proposed since such materials may be surface of the cap or on the external surface of sufficientl rigid to allow for the formation of a the bottle neck and being movable into the anscrew thread, and yet be flexible enough to seal nular groove to form a seal between the cap and the bottle without the use of a sealing insert or bottle neck. In order .to move the bead and Bottle caps molded in conventional groove into interlocking engagement, the cap shapes from polyethylene are not satisfactory due must be turned down on the bottle neck, and in to a thread stripping cap loosening action which so doing, the skirt of the bottle cap is deformed takes place when the glass threads are wetted outwardly before the bead can move inwardly with a liquid, such as oil or liquid soap, contained into interlocking engagement with the groove The conventional molded round provided therefor; thread results in a production of a radially outlooking engagement with the groove, the tension ward component of force which distorts the cap due to the deformation of the cap skirt is lessened, skirt radially outwardly to allow it to move out but the groove is provided with smaller dimenof engagement with the threads on the bottle sions than the dimensions of the bead so that neck to which the cap is applied. In addition, tension will be maintained in the material of the when the caps are screwed onto a wetted bottle 49 cap skirt for holding the abutting surfaces of the neck with sufficient force to form a seal with the annular bead and groove in sealing engagement bottle neck, the axial force on the bottle cap with each other. In addition to the seal provided results in the cap rotating in a direction effective by'the bead and groove; an interlocking action to loosen itself an amount sufficient to interrupt is had which is effective to prevent a self-turning action of the bottle cap on the bottle neck in Polyethylene cap closures may be improved by a direction to disengage the cap from the bottle providing substantially square threads on the neck due to the interlockpreventing axial movecap and bottle neck in place of the rounded ment of the cap the bottle neckthreads provided conventionally on molded bottle Other objects and advantages of the invention The provision of square threads will become apparent from the following descripreduces the radially outward component of force tion. j against the cap skirt and thereby the tendency of In the' drawings, there is shown a preferred the'skirt to deform when screwed tightly on a embodiment of the invention. In this showing: bottle neck and thus allow disengagement or Fig.1 is a fragmentary verticalsectionalview of" a bottle with a cap closure-memberthereon illustrating a preferred embodiment of the invention;

Fig. 2 is a view similar to Fig. 1 illustrating a modified embodiment of the invention;

Fig. 3 is a view similar to Fig. 2, but showing conventional round threads on the cap and bottle neck in place of the square threads shown in Fig. 2;

Fig. 4 is a view similar to Fig. 1 showing the interlocking bead and groove in different positions;

Fig. is a view similar to Fig. 4 in which the bead on the bottle is illustrated as having a cor" rugated surface;

Fig. 6 is an enlarged fragmentary sectional view of a part of the structure shown in Fig. 1; and

Fig. '7 is a view similar to Fig. 1 illustrating a structure in which the bottle and the base of the cap skirt have abutting surfaces.

In the drawings, the numeral I designates the neck of a glass bottle having threads on the external surface thereof for engagement with cooperating threads formed on the internal surface of a threaded opening in a cap closure mem her 2. The cap closure member 2 is constructed by molding from resilient flexible material, such as the preferred plastic material, polyethylene, although other materials exhibiting similar properties may be used as pointed out above. The bottle neck I may be provided with either square threads 3 for engagement with similar threads on the internal surface of the cap 2 or conventionally-shaped round threads 4 as illustrated in Fig. 3. The use of square threads 3 is preferred since such threads minimize the self-stripping action or possibility of thread disengagement.

In order to provide a seal between the bottle cap and the bottle neck, there is provided an annular bead 5 for movement into interlocking engagement with an annular groove 6. Engagement of the bead 5 in the groove 6 provides an interlock to prevent axial movement of the cap on the bottle neck. As shown in Fig. l, the bead 5 is formed on the internal surface of the cap skirt 1 for engagement in a groove 6 formed on H the external surface of the bottle neck adjacent the bottle lip 8. Alternatively, as shown in Fig. 4, the bead 5' may be formed on the bottle neck for engagement in a groove 6' in the cap skirt 7, and positioned on the bottle side of the threads 3 rather than the lip side of the threads 3 as shown in Fig. 1.

In order for the bead 5 to move into interlocking engagement with the groove 6, it is necessary to deform the skirt I of the cap 2 radially outwardly before the bead can move into the groove 6. Referring to Fig. 1, for example, when the cap 2 is screwed onto the neck I, the threads 3 will move the cap axially downwardly until the bead 5 strikes the pour-lip edge 8 of the bottle. Continued downward movement of the cap 2 will cause the skirt i opposite the bead 5 to deform radially outwardly. This deformation of the skirt '1 will tension the skirt, and the bead 5 will move into the groove 6 when the cap moves to the position shown in Fig. 1. The dimensions of the groove 6 are made less than the dimensions of the bead 5 so that all the tension on the skirt 1 will not be released when the bead 5 moves into the groove 6. The tension remaining in the skirt 1 will thus be effective to maintain abutting surfaces of the bead 5 and groove 6 in sealing engagement with each other.

The bead 5 and groove 6 are so axially located with respect to the lip 9 of the bottle that they move into interlocking engagement at about the same time the inner surface ll! of the cap 2 moves into abutting engagement with the surface of the lip 9 of the bottle. In this manner a seal will be provided both by the abutting surfaces 9 and I0 and by the abutting surfaces on the bead 5 and groove 5. In order to insure that the surfaces 9 and IE] will be maintained in abutting and sealing engagement, the axial distance between the bead 5 and the surface it is made a trifle less than the axial distance between the groove 6 and the bottle lip 9, as shown in Fig. 1. In this manner, the tension moving the bead 5 into the groove 6 will set up a force in the cap in an axial direction which will be effective to maintain the surface It in sealing engagement with the bottle lip 9. Due to the stretching action on the material of the cap 2 by reason of the force holding the surface E0 in engagement with the surface 2, the cap 2 will also have sealing engagement with the bottle in an annular area about the pour-lip 8. With the bead 5 engaged in the groove 6, the cap will have a sealing engagement with the bottle neck at three different points; namely, between the abutting surfaces of the bead 5 and the groove 6, in the annular area about the pouring lip 9, and between the abutting surfaces 8 and I0. Regardless of how tightly the cap 2 is screwed on a bottle the sealing engagement will always be effective in at least one of the three points named in connection with the modification shown in Fig. 1.

In addition to the sealing action provided by the abuttingly engaged surfaces of the bead 5 and groove 5, movement of the bead 5 into the groove 6 sets up an interlock between the cap 2 and bottle neck I which is effective to prevent movement of the cap '2 in an axial direction with respect to the bottle neck I. This interlocking action is thus effective to prevent accidental rotation of the cap 2 with respect to the bottle neck I. This interlock is elfective to prevent any selfloosening action of a polyethylene cap on a bottle even though its threads are wet with a lubricating liquid.

In the modification shown in Fig. 2, the cap 2 and bottle neck l are provided with a dove-tail interlock in place of the cooperating groove 6 and bead 5 of l. The dove-tail interlock is provided by a tapered under-cut groove H on the outer surface of the bottle neck adjacent its pour-lip 9 and an annular ridge 12 with reverse under-cut on the inner surface of the cap skirt 7 for mating engagement with the groove l I. In order to move the ridge [2 into the groove II, the skirt 1 must be deformed outwardly opposite the ridge before the ridge I2 can move into the groove ll. Due to the reverse tapers of the engaging surfaces on the groove H and ridge 12, an axial component is set up tending to maintain the surfaces 9 and In in engagement with each other. This structure will provide the same action as is provided by the arrangement of the bead 5 and groove 6 of Fig. 1.

As pointed out above, the structure shown in Fig. 3 is the same as that shown in Fig. 2 except that conventional round threads 4 are provided in place of the square threads 3 of Fig. 2. The operation of the structure shown in Fig. 3 will function to provide seals and to prevent selfloosening of the cap 2 on the bottle neck I in the same manner as described in connection with the structure shown in Fig. 2.

In the modification shown in Fig. 4, an interlocking bead '5' is formed ontheb'ottle neck I in place of on the internal surfaceof the skirt 7* as shown in Fig. 1; In this modificationythe groove 6 is formed on the internal surface of the skirt 1 and is adapted to receivethe bead when the cap is screweddown-on thebottle neck. In this modification, the skirt 1 will flex outwardly as the cap 2 is moved into a position in which the bottle bead 5 will moveintothe cap groove 5. The bottle bead 5 is so'located' with respect to the bottle lip 9- that it moves into interlocking engagement with the cap groove 6' when the bottle lip 9 moves into abutting and sealing engagement with the surface H) of the cap. In this modification, reliance is placed mainly on the seal provided by abutting engagement between the surfaces 9 and 10' although the engagement of the bottle-bead 5 in the cap groove 63' will function as a seal to'prevent' leakage of any fluid which may get past theseal at the bottle lip 8. Engagement'of'the bottle bead 5 in the cap groove 6 providesan-interlock to prevent axial and rotational movement of the cap 2 on the bottle I as described above. Inthis modification, the bead 5"is provided with larger dimensions than the groove '6' so that tension will be maintained on the skirt I to keepthe surfaces of the head 5' and groove 6 in'sealing engagement with each other.

. In the modification shown in Fig. 5, the bottle bead 5" is illustrated as havinga corrugated surface. The provision of a corrugated surface on the bead 5" is desirable in that it functions to additionally prevent rotational movement of the cap 2 on the bottle neck I.

The structure shown in Fig. 7 is similar to that illustrated in Fig. 1 and like numerals have been employed to designate like parts. In this showing, the bottle is shown as having a planar surface it for engagement with the surface l5 at the base of the cap-skirt'l The: surfaces l4 and it are arranged to move into abutting engagement just after the surfaces 9 and I0 move into sealing engagement. The purpose of having-the surfaces i4 and I5 move into abutting'engagement is to preventtightening of the cap, with consequent stretching of theskirt 1, an amount effective to enable a thread skipping or jumping action. Although the-"cap and bottle'in Fig. 7 are illustrated as having square threads,-it will be understood that action provided by the surfaces Hi and i5 is best adapted to the prevention of thread skipping where the cap is provided with conventional round threads as in Fig. 3;

The operation of the cap of this invention will be apparent from the foregoing, but attflntionis directed to the fact-that the interlock against axial movement is effected automatically by the conventional operation of screwing the cap on a bottle neck. This operation is operative first to automatically expand the skirt 1, and the resulting tension in the skirt will move the parts, such as the bead 5, ridge I2, or groove 6, inwardly into interlocking engagement. By making these parts of larger dimension than the cooperating parts on the cap, the skirt 1 is kept under tension to maintain the interlocked surfaces in liquid sealing engagement. As in the modifications shown in Figs. 1 and 2, this tension reacts to produce a pull in an axial direction on the cap for maintaining the surfaces 9 and ID in liquid sealing engagement.

While I have illustrated and described one specific embodiment of my invention, it will be understood that this is merely by Way of illusmovement of the closure element off of the neck element, the surfaces of said elements defining said ridge and groove being operable to expand said closure element in its application to said neck element to provide tension for maintaining said ridge and groove in abutting engagement to provide a liquid seal therebetween.

2. For use on a glass bottle having a neck with a pour lip at its end, external threads spaced inwardly of said lip, and an annular groove on the external surface of the bottle neck between said lip and external threads, a closure formed of elastic and deformable material having an end portion forabutting and sealing engagement with said lip and an integral cylindrical skirt portion with internal threads for engagement with said external bottle neck threads to move said end portion into abutting engagement with said lip upon rotation of the closure on the bottle neck, tightening of said closure on said neck being effective to compress said lip into the material of said end portion to form a fluid seal therewith, and an annular ridge on the inner surface of said skirt portion between said internal threads and end portion for fluid sealing engagement with the bottle neck annular groove, said ridge being spaced axially from said end portion a distance less than the distance between said lip and bottle neck groove, the tightening of said closure on said neck to form a seal between said lip and end portion being effective to stretch said skirt axially to-position said ridge for movement into said groove, saidridge having an internal diameter less than the external diameter of the bottle neck so that said skirt is stretched radially in the application of the closure to the bottle neck, the tension of the skirt from said radial stretch and said axial stretch being effective to maintain said ridge engaged tightly in said groove to provide an additional fluid seal, and to prevent uncontrolled axial and rotational movements of said closure on thebottle neck.

3. For use on a glass bottle having a neck with a pour lip at its end, external threads spaced inwardly of said lip, and an annular groove on the external surface of the bottle neck between said lip and external threads, a closure formed of elastic and deformable material having an end portion for abutting and sealing engagement with said lip and an integral cylindrical skirt portion with internal threads for engagement with said external bottle neck threads to move said end portion into abutting engagement with said lip upon rotation of the closure on the bottle neck, tightening of said closure on said neck being effective to compress said lip into the material of said end portion to form a fiuid seal therewith, and an annular ridge on the inner surface of said skirt portion between said internal threads and end portion for fluid sealing engagement with the bottle neck annular groove, said ridge being spaced axially from said end portion a distance less than the distance between said lip and bottle neck groove, the tightening of said closure on said neck to form a seal between said lip and end portion being effective to stretch said skirt axially to position said ridge for movement into said groove, said internal and external threads being substantially square whereby the tightening force applied to said skirt portion is applied substantially entirely in an axial direction, said ridge having an internal diameter less than the external diameter of the bottle neck so that said skirt is stretched radially in the application of the closure to the bottle neck, the tension of the skirt from said radial stretch and said axial stretch being eiiective to maintain said ridge engaged tightly in said groove to provide an additional fluid seal, and to prevent uncontrolled axial and rotational movements of said closure on the bottle neck.

4. The combination comprising a bottle and a closure therefor, said bottle having a neck with external threads, a pour lip at its outer end, and an annular groove on its external surface intermediate said lip and external threads, said closure being formed of elastic and deformable material having an end portion for abutting and sealing engagement with said lip and an integral cylindrical skirt portion with internal threads for engagement with said external bottle neck threads, rotation of said closure on said neck being effective to move said closure axially to compress said lip into the material of said end portion to form a fluid seal therewith, and an annular ridge on the inner surface of said skirt portion between said internal threads and end portion for fluid sealing engagement with the bottle neck annular groove, said ridge being spaced axially from said end portion a distance less than the distance between said lip and bottle neck groove, rotation of said closure on said neck after sealing engagement of said end portion with said lip being effective to stretch said skirt axially to position said ridge for movement into said groove, said internal and external threads being substantially square whereby the tightening force applied to said skirt portion is applied substantially entirely in an axial direction, said ridge having an internal diameter less than the external diameter of the bottle neck so that said skirt is stretched radially in the application of the closure to the bottle neck, the tension of the skirt from said radial stretch and said axial stretch being effective to maintain said ridge engaged tightly in said groove to provide an additional fluid seal, and to prevent uncontrolled axial and rotational movements of said closure on the bottle neck.

5. For use on a glass bottle having a neck portion with a pour lip at its end and external threads spaced inwardly of said lip, a closure formed of elastic and deformable material having an inner end surface for abutting and sealing engagement with said lip and an integral cylindrical skirt portion with internal threads for engagement with said external bottle neck threads to move said end surface into abutting engagement with said lip upon rotation of the closure on the bottle neck, tightening of said closure on said neck being effective to compress said lip into the material forming said end surface and into fluid sealing engagement therewith, said neck and skirt portions respectively having annular and concentric facing surfaces one of which is provided with an annular ridge and the other of which is provided with an annular groove in which the annular ridge is receivable, the axial spacings of said ridge and said groove on said portions with respect to said pour lip and to said end surface being relatively different whereby said skirt portion must be stretched in an axial direction to position said ridge for engagement in said groove, tightening of said closure on said neck to form a seal between said lip and end surface being efiective to stretch said skirt axially to position said ridge for engagement in said groove, said ridge having a radial depth greater than the radial depth of said groove and projecting beyond the said annular surface in which said groove is formed so that said skirt is stretched radially in the application of the closure to the bottle neck, the tension of the skirt from said radial stretch and said axial stretch being eiiective to maintain said ridge engaged tightly in said groove to provide an additional fluid seal and to prevent uncontrolled axial and rotational movements of said closure on the bottle neck.

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